This invention relates generally to photographic flash devices, and more particularly to a light-diverting attachment that readily mounts over the light-projecting aperture of a photographic flash unit, for selectively projecting light onto a photographic subject at various oblique angles relative to the focal axis of the flash unit.
Most photographers rely on electronic stroboscopic and/or incandescent bulb photographic flash units for illuminating a subject when natural light is insufficient or unavailable. Commonly, such flash units detachably mount on the camera itself, or form an integral part thereof. As a consequence, light emanating from the camera-mounted flash device illuminates the subject uniformly, in a plane parallel to the camera lens. Such "head-on" illumination bathes the subject in light and results in minimal shadow detail, poor texture rendition, and a flat or shallow perspective. And worse, such illumination can cause the eyes of human subjects to appear red as a result of light reflecting from blood vessels within the subject's eyes.
One solution to the problems attendant to head-on lighting is to place the flash unit so that light will be projected at an angle to the focal axis of the camera lens. This angular light projection accentuates shadow detail thereby enhancing the depth characteristics of the photograph and gives the subject a more life-like appearance. Angular lighting also avoids intense illumination of the blood vessels of the subject's eyes, thus eliminating an undesirable "red eye" effect.
There are hand-held photoflash units that can effect this angular light projection if held out at arms length, but these units are comparatively expensive and more difficult to handle than camera-mounted units.
Some camera-mounted flash units effect angular light projection with a tiltable or rotatable light-projecting aperture. These units are designed to bounce light from the ceiling or adjacent walls onto the subject. While bounce lighting does enhance depth and improve texture, as well as mitigate the troublesome red eye effect, it cannot be effectively used where the color of the walls or ceilings might absorb a major portion of the illumination or might impart an unwanted tint onto the subject.
There is, then, the need for a simple, inexpensive means for adapting a camera-mounted flash unit to provide angular light projection now available only with bulky hand-held units, or with frequently ineffective bounce lighting units.